Method of relieving strains in a wall and construction therefor

ABSTRACT

A method for and construction resulting from scoring the paper cover sheet of a gypsum wallboard from corners of openings therein to relieve strains and control cracking of the wallboard.

[ Jan. 22, 1974 5/1968 2/1909 Friedman et 6/1939 Ballet 6/1966Mosely............

ABSTRACT 7 Claims, 7 Drawing Figures Primary Examiner-Price C. Faw, Jr.Attorney, Agent, or Firm-James W. Grace A method for and constructionresulting from scoring the paper cover sheet of a gypsum wallboard fromcorners of openings therein to relieve strains and control cracking ofthe wallboard.

David P. Kasprzak, Largo, Fla.

The Celotex Corporation, Tampa, Fla.

May 3, 1972 References Cited Wilson et 28 ['7 6 m l l 1 1 1 kl 1 1 1 1F||l|I1Cf|||1l rilllllkl llL WALL AND CONSTRUCTION THEREFOR Inventor:

[73] Assignee:

UNITED STATES PATENTS United States Patent Kasprzak [5 METHOD OFRELIEVING STRAINS IN A [22] Filed:

211 Appl. No.: 250,075

[58] Field of Search.......

1W 1 l l 1 l 1 1|.111l1 PATENTH] JAN 2 2 I97 FIGZ METHOD OF RELIEVINGSTRAINS IN A WALL AND CONSTRUCTION THEREFOR BACKGROUND OF THEINVENTION 1. Field of the Invention This invention relates to the fieldof building construction and more particularly to the construction ofwalls and partitions in buildings.

2. Description of the Invention In the construction of walls and fullroom height partitions it has been customary to erect framing members one ifier 1 6 or 24 centers to span the distaheeTaetween a floor plate anda header. To finish the wall, gypsum wallboards are secured by fastenersor adhesive to the room-side faces of the framing members. When it isdesireable to have window or door openings in the wall it has beencustomary to align the edges of a wallboard vertically along the face ofa framing member which forms one side of the opening. A second wallboardis aligned along the face of the framing member spaced a distance fromthe first framing member equal to the horizontal dimension of theopening. In the case of a door, the open area between the top lintel andthe room header is closed by means of cutting a smaller piece of gypsumwallboard which is used to span the framing members which form thevertical frame of the doorjamb. In the case ofa window, the openingsabove and below the window opening are covered by similarly cuttingsmall pieces of gypsum wallboard. Thus, for a simple window opening fourpieces of gypsum wallboard are used. Smaller pieces must be cut to fitthe opening. Following the securing of the gypsum wallboard theresulting gaps between the board edges were finished with jointtreatments in the usual manner.

In addition, to using separate pieces of gypsum wallboard which leftgaps between the pieces, it is also customary to provide control joints.These control joints are produced by inserting separate metal or plasticaccessories at and parallel to the jamb studs above and below the windowopenings and above the door openings. If desired, they may also beplaced at predetermined locations in long blank walls. These plastic ormetal accessories are usually u-shaped pieces which can expand andcontract to relieve strains induced by wall movement. The use of suchaccessories requires a more accurate cutting and fitting of thewallboard to fit between control joints.

Additional cost of parts and labor are the result of this prior artsolution to the problem of relieving strains and controlling cracking ofthe wallboard.

It has been found that unless there was a gap between wallboardsoutlining the window or door opening, racking forces and strains wouldresult in cracking of the wallboard from the corners of the openingtoward the outer edge of the board. Mobile homes and modular units whichare moved from factory to site are particularly susceptible to suchforces in transit.

SUMMARY OF THE INVENTION The present invention permits the constructionof a wall using full sheets of gypsum wallboard with openings cut out ofthe board. This eliminates the extra labor of cutting smaller pieces andfitting them between larger boards above and below the desired opening.

It is an object of the present invention to provide a novel method ofcontrolling cracking of wallboards around window and door openings.

It is another object of the present invention to provide a novelconstruction which is time and labor saving.

It is yet another object of the present invention to provide a novelmethod and construction to avoid the use of other accessories inachieving a structure with controlled cracking.

DESCRIPTION OF THE PREFERRED EMBODIMENT Other objects and advantageswill become apparent to those skilled in the art when the followingdetailed description is considered in the light of the drawing in whichlike numerals indicate like elements and in which:

FIG. 1 is a front elevational view of the framing members erected inplace and providing for window and door openings;

FIG. 2 is a front elevational view of a wall with gypsum wallboardssecured over the framing members and covering the window and dooropenings;

FIG. 3 is a front elevational view of the wall of FIG. 2 with the windowand door openings cut out of the gypsum wallboards;

FIG. 4 is an enlarged front elevational view of a portion of the wall ofFIG. 3, illustrating the scoring of the board;

FIG. 5 is a cross-sectional view of the wall portion of FIG. 4 takenalong lines 5-5 thereof;

FIG. 6 is a front elevational view of the wall portion of FIG. 4 with apartial joint treatment applied over the score line; and

FIG. 7 is an elevational view of an alternative type of score line inthe wallboard.

Referring now to the drawing and particularly FIG. 1, there is shown theframing members secured in place to form a wall. Vertical framingmembers 10 span the area between a double header 11 and a double baseplate 12. In general, the framing members, header and plates are 2inches X 4 inches pieces of lumber conventionally used for framing. Ifdesired, 2 inches X 2 inches pieces may be used, as may be morecustomary in the construction of mobile homes.

To accommodate a door opening 15, a lintel 16 is secured to span betweenadjacently spaced vertical framing members 10 at a height suitable forthe installation of a door (not shown). A strengthening vertical framingmember 17 is secured between lintel 16 and header 11.

To define a window opening 18, spaced upper and lower horizontal members20 and 21 are secured between adjacent framing members 10. Strengtheningvertical framing members 23 and 24 span between horizontal member 21 andheader 1 1 and horizontal member 20 and plate 12, respectively.

FIG. 2 illustrates the effect of the next step in constructing the novelconstruction of the invention. Gypsum wallboards 27 31 are fastenedvertically to the various framing members 10, 16, 17, 20, 21, 23 and 24.This can be done by using an adhesive or by using fasteners, such asnails or wallboard screws in the conventional manner or combinations ofthese fasteners.

The front elevational view of the wall after the openings have been cutout of the gypsum wallboard panels 28, 29 and 30 is shown in FIG. 3. Tomake the openings, the tradesman uses a saw or other cutting instrumentand cuts the opening through the gypsum wallboard along the inner faceof the peripheral framing members.

It is thus seen that the erection of the wall with provision for windowand door openings has been greatly simplified in that only large sheetsof gypsum wallboard need be used. However, if nothing further is done,the wallboard may be subject to forces which can cause cracks in it.

Reference may now be had to FIG. 4 to show in detail the novel method ofthe invention which provides for avoiding cracks in the wallboard.

Wallboard 29 is secured to framing member 10 header 11 and horizontalmember 21 by adhesive or other fastening means. Opening 18 is cut intothe wallboard 29 and one of its corners 33 appear at the juncture offraming member 10 and horizontal member 21. The face papers of wallboard29 is scored from the corner 33 to a line 35 along the centerline offraming member 10 and along this line 35 to the upper edge 36 ofwallboard 29.

Of course, wallboard 29 is scored at each of the other corners (notshown) and along the centerlines of the adjacent framing members to thenearest horizontal edge of the wallboard.

FIG. shows in cross-section a detailed view of wallboard 9 with scoreline 35 cut in its upper paper sheet 37. As in conventional gypsumwallboard, there is a core of set cementitious material 39 (gypsum withknown additives) enclosed in adhered paper sheets 37 and 40. Wallboard29 is secured to framing member by a thin layer of adhesive 41. As canbe seen in FIG. 5, score line 35 runs parallel to and along thecenterline of framing member 10. It has been found that it is sufficientto score only the outer sheet 37 of the gypsum wallboard 29.

To provide for finishing the wall and lay a monolithic base forsubsequent application of wallpaper or a paint coating, the score line35 may be given a conventional joint treatment. Typically, thiscomprises applying a first layer of conventional joint compound, a papertape or woven glass scrim 43 is embedded in the moist joint compound,and a finish or top coat 45 of joint compound is applied over theembedded tape. The finish coat is feathered until a smooth monolithicwall surface is achieved. This technique of applying a finishing jointtreatment is well known and described in the art.

As an alternative procedure, the complete joint treatment may be omittedand a thin layer of a suitable adhesive, such as a polyvinyl adhesive orconventional joint compound may be used to keep the paper along thescore line from peeling back from the gypsum core. A suitable finishcoating may be applied over the entire wall surface.

While the score line 35, shown in FIGS. 4 and 5, is shown as acontinuous cut through the outer sheet 37 to the core 39 from beginningto end, starting at the corner 33 proceeding to the edge 36 of thewallboard, it has been found, unexpectedly, that the score line mayconsist of a series of small perforations or cuts which are notinterconnected, but are similar to the perforations which separatestamps in a sheet. This feature is shown in FIG. 7 in which the scoreline is illustrated by a series of small perforations. Disruptive forceswill follow the score line and be relieved therein. Forces of excessivemagnitude may result in a slight hairline crack along the score line.Without the score line, forces of equal magnitude will cause extensiverandom cracking of the wallboard with ply separation of the cover paper.This latter condition requires extensive additional repairs. Thus, theterm score is used in a broad sense and is not to be limited tocontinuous cutting.

While details of the novel method have been described particularly withreference to window opening 18, score lines are connected to the corners48 of door opening 15.

While the figures of drawings illustrate the score line as extendingparallel to the center-line of the framing member, it may in fact extendhorizontally from a corner of the opening to the nearest edge of thewallboard. It has been found to be easier to apply the joint treatmentover a framing member although it need not be done solely in thatmanner. For this reason the preferred embodiment, the score line followsthe centerline of the nearest framing member.

In summary there is shown a novel method and construction to controlcracking in the construction of building walls.

I claim:

1. A method of relieving strains in a monolithic appearing wallcomprising the steps of:

securing to framing members edge-abutting gypsum wallboard panels, eachpanel having a cover sheet. cutting openings having exposed corners insaid gypsum wallboards.

scoring said cover sheets with scores extending from said corners ofsaid openings to the edges of said wallboards, and

applying a cover material over said scores.

2. A method of relieving strains in a monolithic appearing wall as setforth in claim I in which said scoring in said cover sheet begins at anexposed corner of an opening and extends to a point over the center-lineof an adjacent framing member and parallel to said center-line to thenearest edge of the wallboard,

3. A method of relieving strains in a monolithic appearing wall as setforth in claim I in which said scoring comprises a cut continuouslythrough the cover sheet.

4. A method of relieving strains in a monolithic appearing wall as setforth in claim 1 in which said scoring comprises a perforated linethrough the cover sheet.

5. A wall structure comprising parallel spaced framing members securedin upright position,

gypsum wallboard panels secured to said framing members; said gypsumpanels comprising a set gypsum core and outer cover sheets adhered tosaid core, rectangular openings cut out of at least one of said panels;said rectangular openings having exposed comers; score lines cut in oneof said outer cover sheets, leaving a continuous gypsum core behind andextending across said score line, said score lines extending fromrespective exposed corners of said openings to the nearest edges of thewallboard.

6. A wall structure as recited in claim 5 in which each of said scorelines is a continuous cut in said outer cover sheet from said exposedcorner to the nearest edge of the wallboard.

7. A wall structure as recited in claim 5 in which each of said scorelines is a perforated line extending from one of said exposed comers tothe nearest wallboard edge.

1. A method of relieving strains in a monolithic appearing wallcomprising the steps of: securing to framing members edge-abuttinggypsum wallboard panels, each panel having a cover sheet. cuttingopenings having exposed corners in said gypsum wallboards. scoring saidcover sheets with scores extending from said corners of said openings tothe edges of said wallboards, and applying a cover material over saidscores.
 2. A method of relieving strains in a monolithic appearing wallas set forth in claim 1 in which said scoring in said cover sheet beginsat an exposed corner of an opening and extends to a point over thecenter-line of an adjacent framing member and parallel to saidcenter-line to the nearest edge of the wallboard,
 3. A method ofrelieving strains in a monolithic appearing wall as set forth in claim 1in which said scoring comprises a cut continuously through the coversheet.
 4. A method of relieving strains in a monolithic appearing wallas set forth in claim 1 in which said scoring comprises a perforatedline through the cover sheet.
 5. A wall structure comprising parallelspaced framing members secured in upright position, gypsum wallboardpanels secured to said framing members; said gypsum panels comprising aset gypsum core and outer cover sheets adhered to said core, rectangularopenings cut out of at least one of said panels; said rectangularopenings having exposed corners; score lines cut in one of said outercover sheets, leaving a continuous gypsum core behind and extendingacross said score line, said score lines extending from respectiveexposed corners of said openings to the nearest edges of the wallboard.6. A wall structure as recited in claim 5 in which each of said scorelines is a continuous cut in said outer cover sheet from said exposedcorner to the nearest edge of the wallboard.
 7. A wall structure asrecited in claim 5 in which each of said score lines is a perforatedline extending from one of said exposed corners to the nearest wallboardedge.